This game is having a sorts of access issues. It's security related and you'll have to jump through a few hoops to get around them. Your server is still there meanwhile.

Some players have posted workaround links. You can try to use the firefox browser or the mini client. For Firefox, it will ask you about TLS. It's a security compromise if you say yes, but it will let you play the game. For miniclient, you may have to remove the acct from mini client easy access and add it back. This works for me.

People have posted other things in case this doesn't help.

That said @game runners, get this fixed asap. This is on your end, not the players.